This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this study is to determine if there is a relationship between salt sensitivity and genetic variations. Certain genetic patterns may result in a change in the ability of the kidney to get rid of dietary sodium, resulting in sodium and water retention and a subsequent rise in blood pressure. Genetic screening will be performed in up to 3000 people in order to identify those with certain gene profiles. Four hundred (400) of those screened will be invited to participate in two weeks of diets, one week of low salt and one week of high salt, in randomized order. Blood pressure measurements, urine and blood tests will be taken while subjects are on the two weeks of varied salt diets. A significant rise in blood pressure from low salt to high salt diets will indicate salt sensitivity.